This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. It is known that SIV-infected Mamu-A superscript 01+ rhesus macaques develop lower plasma viral loads than Mamu-A*01- monkeys. CD8+ T cells possibly play a role in the control of viremia. To test this hypothesis SIV-specific CD8+ T cells from Mamu-A*01+ (A*02-, B*17-,B*08-) monkeys and Mamu-A*02+ (A*01-, B*17-, B*08-) monkeys are being isolated. Virus-specific CD8+ T cells may be different in Mamu-A*01+ monkeys from those on Mamu-A*02+ monkeys. This difference may be reflected in the RNA transcripts that are present in the virus-specific CD8+ T cells from monkeys with different genotypes.